Method and apparatus for refrigeration machine lubrication



June 25, 1968 J. w. ENDRESS 3,339,569

METHOD AND APPARATUS FOR REFRIGERATION MACHINE LUBRICATION Filed Oct. 27, 1966 6 O O O JD O O O O O O O O O O O O O OOOOO O O O O O ogogogogigo OOOOOOO OOO O O O O O O O O O O O m INVENTOR JAMES W. ENDRESS.

FIG.3

ATTORNEY.

United States Patent 3,389,569 METHOD AND APPARATUS FOR REFRIGERATION MACHINE LUBRICATION James W. Endress, Syracuse, N.Y., assignor to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Filed Oct. 27, 1966, Ser. No. 590,005 Claims. (Cl. 62-84) ABSTRACT OF THE DISCLOSURE Means for cooling and lubricating a refrigeration machine bearing by providing a refrigerant-lubricant mixture to internal passages in the bearing support for cooling the bearing by vaporizing the refrigerant in the mixture, thereby assuring refrigerant-free lubricant for passage to the bearing surface to avoid the deleterious effects of vapor erosion of the bearing surfaces.

This invention relates to refrigeration machines. More particularly, this invention relates to lubrication of a re frigeration machine. Still more particularly, this invention relates to the use of oil enriched refrigerant as a lubricant in a refrigeration machine.

In refrigeration systems, lubricating and cooling the moving parts of the machine present numerous problems. The most acceptable way of accomplishing these objectives is to provide oil for lubrication and liquid refrigerant for cooling. In order to utilize two different liquids in the machine, it is ordinarily necessary to completely seal the lubrication system to prevent oil entrainment of the refrigerant. Since some portions of the machine, such as bearings, must be lubricated and cooled, it has heretofore been the practice to provide means for cooling the oil so that the oil in turn could cool the bearings. The provision of an oil cooler and dependable seals increase the complexity and the cost of the refrigeration system.

It is therefore the chief object of this invention to provide a novel cooling and lubrication system for a refrigeration machine. It is a further object of this invention to provide a refrigeration system employing a lubricant refrigerant mixture for lubricating and cooling various elements of the refrigeration machine.

It is another object of this invention to provide an improved method for cooling and lubricating a refrigeration machine.

The objects of this invention are attained by providing a mixture of lubricant and refrigerant to the exterior of the refrigeration machine bearings, the heat of which evaporates the refrigerant in the mixture. The lubricant thus separated is provided to the bearing surfaces of the machine.

Other objects and features of this invention will be apparent upon a consideration of the ensuing specification and drawings in which:

FIGURE 1 is a sectional view of a refrigeration machine employing my invention;

FIGURE 2 is a partial sectional view taken along line IIII of FIGURE 1; and

FIGURE 3 is a partial sectional view taken along line IIIIII of FIGURE 2.

Referring more particularly to the drawings, there is shown a refrigeration machine 1 having a motor-compressor 3, a condenser 5 and an evaporator 7. A float valve 4 is provided for regulating flow of liquid refrigerant from the condenser to the evaporator. A tube bundle 6 in condenser 5 is supplied with a heat exchange fluid from a suitable source, such as a cooling tower (not shown), to cool the compressed refrigerant supplied thereto from the compressor and cause it to condense therein. A tube bundle 8 is provided in evaporator 7 for passing the medium to be cooled in heat transfer relation with the refriger- 3,389,569 Patented June 25, 1868 ant in the evaporator causing the refrigerant to vaporize and pass to the compressor to complete the refrigerant flow cycle. A lubricant sump 9 having its lower portion 10 below the evaporator chamber 7 communicates with evaporator 7 through drain line 11 and vent 12. A fluid pump 14 having its inlet disposed in sump 9 communicates with motor-compressor 3 through supply line 16 between the pump discharge and the motor compressor hearing assembly 18. A filter 20 is provided in line 16 to filter out particulate matter in the liquid flowing therethrough. While only one supply line 16 and one bearing assembly 18 are shown, it is to be understood that a number of bearing assemblies would be employed throughout the refrigeration machine, bearing assembly 18 being selected as a representative of their general configuration. The aforementioned bearings would also be supplied with lubricant from pump 14.

A preferred embodiment of bearing assembly 18 is illustrated in FIGURES 2 and 3. A bearing housing 22 having a top wall 24, a bottom Wall 25, side walls 26 and 27, an end wall 28 and bearing support section 30 is provided for hearing 32. A portion of the motor-cornpressor power shaft 34 is illustrated journalled in bearing 32.

The refrigeration system of my invention is charged with refrigerant and lubricant. A mixture of lubricant and refrigerant will therefore collect in sump 9. During shutdown, a heater 56 is energized to maintain the temperature of the mixture high enough to vaporize a large proportion of refrigerant in sump 9, the vapor escaping through line 12. The liquid in sump 9 during shut-down is therefore comprised of lubricant with only a small proportion of refrigerant therein. When the refrigeration system is started up, pump 14 is energized and pumps the lubricant and refrigerant mixture from sump 9 through line 16 to hearing support section 30. A series of passages 36 in section 30 in communication with line 16 surround bearing 32. A partition 38 is provided to block passages 36 for purposes to be hereinafter explained. An opening 40 in bearing 32 provides a passageway for lubricant from passages 36 to the clearance space between bearing 32 and shaft 34. The refrigerant-lubricant mixture passes from line 16 through passages 36 where heat from the bearing causes most of the refrigerant in the mixture to vaporize and cool the bearing. The vaporized refrigerant passes through support vent passage 42 into the area defined by bearing housing 22. The remainder of the liquid in passages 36 collects above partition 38 to provide a supply of lubricant to bearing 32 through opening 40. A support chamber 44 is provided to collect lubricant flowing from the ends of bearing 32, chamber 44 having an opening 46 therein for passage of lubricant into the bottom of housing 22 and a vent 48 to provide an escape route for any refrigerant that might have entered the bearing clearance wtih the lubricant and been vaporized therein. A gaseous refrigerant line 50 directs the refrigerant from housing 22 to evaporator 7 while drain line 52 returns the lubricant collected at the bottom of housing 22 to sump 9.

As can be seen from the foregoing, the instant refrigeration system provides an excellent means for lubricating and cooling the moving parts of a refrigeration machine while maintaining the refrigerant used in the actual refrigeration cycle relatively free of lubricant so that cycle efiiciency is not decreased thereby.

While I have described a preferred embodiment of my invention, it is to be understood that the invention is not limited thereto but may be otherwise embodied within the scope of the following claims.

I claim:

1. A method for cooling and lubricating the hearings in a refrigeration machine comprising the steps of:

providing a supply of lubricant-refrigerant mixture in heat transfer relation with the refrigeration machine bearings;

utilizing the heat of the bearings to vaporize the refrigerant in the mixture, thereby cooling the hearings;

passing the vaporized refrigerant to the low pressure side of the refrigeration machine; and

providing the remaining portion of the mixture to the loaded portions of the bearings for lubrication thereof.

2. The method set forth in claim 1 wherein the step of providing a supply of a lubricant-refrigerant mixture in heat transfer relation with the refrigeration machine includes passage of the mixture over a surface of the bearing remote from the surface in engagement with the power shaft of the machine.

3. A cooling and lubrication system for the bearings of a refrigeration machine comprising:

a sump for collecting a mixture of lubricant and liquid refrigerant;

bearing supports for mounting the bearings therein;

means forming passageways between said supports and the bearings for passage of lubricant-refrigerant mixture therethrough;

a vent communicating with the passageways for venting the refrigerant therefrom that has been vaporized by the heat of the bearings; and

means for passing the remaining portion of the mixture from the passageways to the loaded surfaces of the bearings.

4. A cooling and lubrication system according to claim 3 further including a heater disposed in said sump for heating the mixture to vaporize a portion of the refrigerant therein; and

a pump for passing refrigerant from said sump to the passageways between said supports and the bearings; said means forming the passageways including a plurality of circumferential lands formed in said support for mating engagement with said bearings, the grooves therebetween providing the passageways. 5. A cooling and lubrication system according to claim 4 wherein said means for passing the remaining portion of the mixture to the loaded surfaces of the hearings includes a barrier, formed between said lands, for collecting the remaining portion of the mixture, the bearing having an opening therein between the loaded and unloaded surfaces thereof for passage of the collected refrigerant to the loaded surface.

References Cited UNITED STATES PATENTS 3,149,478 9/1964 Anderson et al. 62-505 X 3,188,833 6/1965 Robinson 62-505 3,300,997 1/1967 Kocher 62-505 3,306,074 2/1967 Wilson 62-505 ROBERT A. OLEARY, Primary Exmniner.

W. E. WAYNER, Assistant Examiner. 

